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Gut Sep 2021Approximately 5% of individuals infected with hepatitis B virus (HBV) are coinfected with hepatitis D virus (HDV). Chronic HBV/HDV coinfection is associated with an... (Review)
Review
Approximately 5% of individuals infected with hepatitis B virus (HBV) are coinfected with hepatitis D virus (HDV). Chronic HBV/HDV coinfection is associated with an unfavourable outcome, with many patients developing liver cirrhosis, liver failure and eventually hepatocellular carcinoma within 5-10 years. The identification of the HBV/HDV receptor and the development of novel in vitro and animal infection models allowed a more detailed study of the HDV life cycle in recent years, facilitating the development of specific antiviral drugs. The characterisation of HDV-specific CD4+ and CD8+T cell epitopes in untreated and treated patients also permitted a more precise understanding of HDV immunobiology and possibly paves the way for immunotherapeutic strategies to support upcoming specific therapies targeting viral or host factors. Pegylated interferon-α has been used for treating HDV patients for the last 30 years with only limited sustained responses. Here we describe novel treatment options with regard to their mode of action and their clinical effectiveness. Of those, the entry-inhibitor bulevirtide (formerly known as myrcludex B) received conditional marketing authorisation in the European Union (EU) in 2020 (Hepcludex). One additional drug, the prenylation inhibitor lonafarnib, is currently under investigation in phase III clinical trials. Other treatment strategies aim at targeting hepatitis B surface antigen, including the nucleic acid polymer REP2139Ca. These recent advances in HDV virology, immunology and treatment are important steps to make HDV a less difficult-to-treat virus and will be discussed.
Topics: Adaptive Immunity; Animals; Hepatitis D; Hepatitis D, Chronic; Hepatitis Delta Virus; Humans; Immunity, Innate
PubMed: 34103404
DOI: 10.1136/gutjnl-2020-323888 -
ELife Nov 2012Human hepatitis B virus (HBV) infection and HBV-related diseases remain a major public health problem. Individuals coinfected with its satellite hepatitis D virus (HDV)...
Human hepatitis B virus (HBV) infection and HBV-related diseases remain a major public health problem. Individuals coinfected with its satellite hepatitis D virus (HDV) have more severe disease. Cellular entry of both viruses is mediated by HBV envelope proteins. The pre-S1 domain of the large envelope protein is a key determinant for receptor(s) binding. However, the identity of the receptor(s) is unknown. Here, by using near zero distance photo-cross-linking and tandem affinity purification, we revealed that the receptor-binding region of pre-S1 specifically interacts with sodium taurocholate cotransporting polypeptide (NTCP), a multiple transmembrane transporter predominantly expressed in the liver. Silencing NTCP inhibited HBV and HDV infection, while exogenous NTCP expression rendered nonsusceptible hepatocarcinoma cells susceptible to these viral infections. Moreover, replacing amino acids 157-165 of nonfunctional monkey NTCP with the human counterpart conferred its ability in supporting both viral infections. Our results demonstrate that NTCP is a functional receptor for HBV and HDV.DOI:http://dx.doi.org/10.7554/eLife.00049.001.
Topics: Amino Acid Sequence; Animals; Biological Transport; Cell Line; Gene Expression; Hepatitis B virus; Hepatitis Delta Virus; Hepatocytes; Humans; Liver; Molecular Sequence Data; Organic Anion Transporters, Sodium-Dependent; Peptides; Photochemical Processes; Primary Cell Culture; Protein Binding; Protein Structure, Tertiary; Receptors, Virus; Symporters; Taurocholic Acid; Tupaia; Viral Envelope Proteins; Virus Internalization
PubMed: 23150796
DOI: 10.7554/eLife.00049 -
Viruses Aug 2022Hepatitis D is the most severe viral hepatitis. Hepatitis D virus (HDV) has a very small RNA genome with unique biological properties. It requires for infection the... (Review)
Review
Hepatitis D is the most severe viral hepatitis. Hepatitis D virus (HDV) has a very small RNA genome with unique biological properties. It requires for infection the presence of hepatitis B virus (HBV) and is transmitted parenterally, mainly by superinfection of HBsAg carriers who then develop chronic hepatitis D. HDV has been brought under control in high-income countries by the implementation of HBV vaccination, and the clinical pattern has changed to a chronic hepatitis D seen in ageing patients with advanced fibrotic disease; the disease remains a major health concern in developing countries of Africa and Asia. Every HBsAg-positive subject should be tested for HDV serum markers by reflex testing, independently of clinical status. Vaccination against HBV provides the best prophylaxis against hepatitis D. The only therapy available so far has been the poorly performing Interferon alfa; however, several new and promising therapeutic approaches are under study.
Topics: Hepatitis B; Hepatitis B Surface Antigens; Hepatitis B virus; Hepatitis D; Hepatitis D, Chronic; Hepatitis Delta Virus; Humans
PubMed: 36016371
DOI: 10.3390/v14081749 -
World Journal of Gastroenterology Jun 2021This review aims to summarize the current evidence on the treatment of viral hepatitis, focusing on its clinical management. Also, future treatment options and areas of... (Review)
Review
This review aims to summarize the current evidence on the treatment of viral hepatitis, focusing on its clinical management. Also, future treatment options and areas of potential research interest are detailed. PubMed and Scopus databases were searched for primary studies published within the last ten years. Keywords included hepatitis A virus, hepatitis B virus (HBV), hepatitis C virus, hepatitis D virus (HDV), hepatitis E virus, and treatment. Outcomes reported in the studies were summarized, tabulated, and synthesized. Significant advances in viral hepatitis treatment were accomplished, such as the advent of curative therapies for hepatitis C and the development and improvement of hepatitis A, hepatitis B, and hepatitis E vaccination. Drugs that cure hepatitis B, going beyond viral suppression, are so far unavailable; however, targeted antiviral drugs against HBV (immunomodulatory therapies and gene silencing technologies) are promising approaches to eradicating the virus. Ultimately, high vaccination coverage and large-scale test-and-treat programmes with high screening rates may eliminate viral hepatitis and mitigate their burden on health systems. The development of curative hepatitis C treatment renewed the enthusiasm for curing hepatitis B, albeit further investigation is required. Novel therapeutic options targeting HDV life cycle are currently under clinical investigation.
Topics: Antiviral Agents; Hepatitis B; Hepatitis B virus; Hepatitis C; Hepatitis D; Hepatitis Delta Virus; Humans
PubMed: 34163109
DOI: 10.3748/wjg.v27.i23.3249 -
Viruses May 2021Hepatitis D virus (HDV) is a small, defective RNA virus that depends on hepatitis B virus (HBV) for virion assembly and transmission. It replicates within the nucleus of... (Review)
Review
Hepatitis D virus (HDV) is a small, defective RNA virus that depends on hepatitis B virus (HBV) for virion assembly and transmission. It replicates within the nucleus of hepatocytes and interacts with several cellular proteins. Chronic hepatitis D is a severe and progressive disease, leading to cirrhosis in up to 80% of cases. A high proportion of patients die of liver decompensation or hepatocellular carcinoma (HCC), but the lack of large prospective studies has made it difficult to precisely define the rate of these long-term complications. In particular, the question of whether HDV is an oncogenic virus has been a matter of debate. Studies conducted over the past decade provided evidence that HDV is associated with a significantly higher risk of developing HCC compared to HBV monoinfection. However, the mechanisms whereby HDV promotes liver cancer remain elusive. Recent data have demonstrated that the molecular profile of HCC-HDV is unique and distinct from that of HBV-HCC, with an enrichment of upregulated genes involved in cell-cycle/DNA replication, and DNA damage and repair, which point to genome instability as an important mechanism of HDV hepatocarcinogenesis. These data suggest that HBV and HDV promote carcinogenesis by distinct molecular mechanisms despite the obligatory dependence of HDV on HBV.
Topics: Carcinogenesis; Carcinoma, Hepatocellular; Genome, Viral; Hepatitis B virus; Hepatitis D; Hepatitis D, Chronic; Hepatitis Delta Virus; Hepatocytes; Humans; Liver Cirrhosis; Liver Neoplasms; RNA, Viral; Virus Assembly
PubMed: 34064419
DOI: 10.3390/v13050830 -
Viruses Jun 2021Hepatitis delta virus (HDV) is a defective human virus that lacks the ability to produce its own envelope proteins and is thus dependent on the presence of a helper... (Review)
Review
Hepatitis delta virus (HDV) is a defective human virus that lacks the ability to produce its own envelope proteins and is thus dependent on the presence of a helper virus, which provides its surface proteins to produce infectious particles. Hepatitis B virus (HBV) was so far thought to be the only helper virus described to be associated with HDV. However, recent studies showed that divergent HDV-like viruses could be detected in fishes, birds, amphibians, and invertebrates, without evidence of any HBV-like agent supporting infection. Another recent study demonstrated that HDV can be transmitted and propagated in experimental infections ex vivo and in vivo by different enveloped viruses unrelated to HBV, including hepatitis C virus (HCV) and flaviviruses such as Dengue and West Nile virus. All this new evidence, in addition to the identification of novel virus species within a large range of hosts in absence of HBV, suggests that deltaviruses may take advantage of a large spectrum of helper viruses and raises questions about HDV origins and evolution.
Topics: Animals; Evolution, Molecular; Genome, Viral; Helper Viruses; Hepatitis D; Hepatitis Delta Virus; Host Specificity; Humans; Phylogeny; Viral Proteins; Virus Replication
PubMed: 34201626
DOI: 10.3390/v13071207 -
Cold Spring Harbor Perspectives in... Jul 2015Hepatitis D is caused by the hepatitis D virus (HDV), a unique RNA pathogen that requires the hepatitis B surface antigen (HBsAg) to infect. Hepatitis D is transmitted... (Review)
Review
Hepatitis D is caused by the hepatitis D virus (HDV), a unique RNA pathogen that requires the hepatitis B surface antigen (HBsAg) to infect. Hepatitis D is transmitted by the parenteral route. The main susceptible group is patients with chronic HBsAg infection who become superinfected with the virus. Hepatitis D occurs throughout the globe, but control of hepatitis B virus (HBV) in the last two decades has consistently diminished the circulation of HDV in industrialized countries. However, hepatitis D remains a medical issue for injecting drug users (IDUs), as well as immigrants from endemic HDV areas, who are reintroducing the infection in Europe.
Topics: Drug Users; Europe; Hepatitis B Surface Antigens; Hepatitis B virus; Hepatitis D; Hepatitis Delta Virus; Humans; Superinfection
PubMed: 26134842
DOI: 10.1101/cshperspect.a021576 -
Viruses Nov 2020Chronic hepatitis D (CHD) is the most severe form of viral hepatitis, with rapid progression of liver-related diseases and high rates of development of hepatocellular... (Review)
Review
Chronic hepatitis D (CHD) is the most severe form of viral hepatitis, with rapid progression of liver-related diseases and high rates of development of hepatocellular carcinoma. The causative agent, hepatitis D virus (HDV), contains a small (approximately 1.7 kb) highly self-pairing single-strand circular RNA genome that assembles with the HDV antigen to form a ribonucleoprotein (RNP) complex. HDV depends on hepatitis B virus (HBV) envelope proteins for envelopment and de novo hepatocyte entry; however, its intracellular RNA replication is autonomous. In addition, HDV can amplify HBV independently through cell division. Cellular innate immune responses, mainly interferon (IFN) response, are crucial for controlling invading viruses, while viruses counteract these responses to favor their propagation. In contrast to HBV, HDV activates profound IFN response through the melanoma differentiation antigen 5 (MDA5) pathway. This cellular response efficiently suppresses cell-division-mediated HDV spread and, to some extent, early stages of HDV de novo infection, but only marginally impairs RNA replication in resting hepatocytes. In this review, we summarize the current knowledge on HDV structure, replication, and persistence and subsequently focus on the interplay between HDV and IFN response, including IFN activation, sensing, antiviral effects, and viral countermeasures. Finally, we discuss crosstalk with HBV.
Topics: Animals; Hepatitis B virus; Hepatitis D, Chronic; Hepatitis Delta Virus; Hepatocytes; Humans; Immunity, Innate; Interferon-Induced Helicase, IFIH1; Interferons; Mice; Virus Replication
PubMed: 33233762
DOI: 10.3390/v12111334 -
Clinical Medicine (London, England) Jul 2023Hepatitis D virus (HDV), also referred to as hepatitis delta virus, is the smallest virus capable of causing human disease. It is unable to replicate on its own and can... (Review)
Review
Hepatitis D virus (HDV), also referred to as hepatitis delta virus, is the smallest virus capable of causing human disease. It is unable to replicate on its own and can only propagate in the presence of hepatitis B virus (HBV). Infection with both HBV and HDV frequently results in more severe disease than HBV alone, with higher instances of cirrhosis, liver failure and hepatocellular carcinoma (HCC). Thus, there is a need for effective treatment for HDV; however, currently approved treatment options are very limited both in terms of their efficacy and availability. This makes the management of HDV a challenge for physicians. In this review, we look at the background, diagnosis and treatment of HDV, informed by our hospital data, to set out the optimal management of HDV; we also explore novel treatment options for this disease.
Topics: Humans; Hepatitis Delta Virus; Antiviral Agents; Carcinoma, Hepatocellular; Liver Neoplasms; Hepatitis B virus
PubMed: 37353306
DOI: 10.7861/clinmed.2022-0556 -
Emerging Microbes & Infections Dec 2023Hepatitis delta virus (HDV) infection accelerates the progression of chronic hepatitis B virus (HBV) infection, posing a large economic and health burden to patients. At...
BACKGROUND & AIMS
Hepatitis delta virus (HDV) infection accelerates the progression of chronic hepatitis B virus (HBV) infection, posing a large economic and health burden to patients. At present, there remains a lack of accurate and portable detection methods for HDV RNA. Here, we aim to establish a convenient, rapid, highly sensitive and specific method to detect HDV RNA using CRISPR-Cas13a technology.
METHODS
We established fluorescence (F) and lateral flow strip (L) assays based on CRISPR-Cas13a combined with RT-PCR and RT-RAA for HDV RNA detection, respectively. we conducted a cohort study of 144 patients with HDV-IgG positive to evaluate the CRISPR-Cas13a diagnostic performance for identifying HDV in clinical samples, compared to RT-qPCR and RT-ddPCR.
RESULTS
For synthetic HDV RNA plasmids, the sensitivity of RT-PCR-CRISPR-based fluorescence assays was 1 copy/μL, higher than that of RT-qPCR (10 copies/μL) and RT-ddPCR (10 copies/μL); for HDV RNA-positive samples, the sensitivity of RT-RAA-CRISPR-based fluorescence and lateral flow strip assays was 10 copies/μL, as low as that of RT-qPCR and RT-ddPCR, and the assay took only approximately 85 min. Additionally, the positivity rates of anti-HDV IgG-positive samples detected by the RT-qPCR, RT-ddPCR, RT-PCR-CRISPR fluorescence and RT-RAA-CRISPR lateral flow strip methods were 66.7% (96/144), 76.4% (110/144), 81.9% (118/144), and 72.2% (104/144), respectively.
CONCLUSIONS
We developed a highly sensitive and specific, as well as a portable and easy CRISPR-based assay for the detection of HDV RNA, which could be a prospective measure for monitoring the development of HDV infection and evaluating the therapeutic effect.
Topics: Humans; Hepatitis Delta Virus; Hepatitis B, Chronic; Cohort Studies; Prospective Studies; RNA, Viral; Immunoglobulin G; Sensitivity and Specificity
PubMed: 37882492
DOI: 10.1080/22221751.2023.2276337